/***************************************************************************************
 *
 *  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
 *
 *  By downloading, copying, installing or using the software you agree to this license.
 *  If you do not agree to this license, do not download, install, 
 *  copy or use the software.
 *
 *  Copyright (C) 2010-2014, Happytimesoft Corporation, all rights reserved.
 *
 *  Redistribution and use in binary forms, with or without modification, are permitted.
 *
 *  Unless required by applicable law or agreed to in writing, software distributed 
 *  under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 *  CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
 *  language governing permissions and limitations under the License.
 *
****************************************************************************************/

#include <stdio.h>
#include <string.h>
#include "sha1.h"


#define GET_UINT32(n,b,i)               	\
{                               			\
	(n) = ( (uint32) (b)[(i)   ] << 24 )	\
	| ( (uint32) (b)[(i) + 1] << 16 )		\
	| ( (uint32) (b)[(i) + 2] << 8 ) 		\
	| ( (uint32) (b)[(i) + 3]     ); 		\
}

#define PUT_UINT32(n,b,i)               	\
{                               			\
	(b)[(i)   ] = (uint8) ( (n) >> 24 ); 	\
	(b)[(i) + 1] = (uint8) ( (n) >> 16 ); 	\
	(b)[(i) + 2] = (uint8) ( (n) >> 8 ); 	\
	(b)[(i) + 3] = (uint8) ( (n)     );     \
}

void sha1_starts(sha1_context *ctx)
{
	ctx->total[0] = 0;
	ctx->total[1] = 0;

	ctx->state[0] = 0x67452301;
	ctx->state[1] = 0xEFCDAB89;
	ctx->state[2] = 0x98BADCFE;
	ctx->state[3] = 0x10325476;
	ctx->state[4] = 0xC3D2E1F0;
}

void sha1_process(sha1_context *ctx, uint8 data[64])
{
	uint32 temp, W[16], A, B, C, D, E;

	GET_UINT32( W[0], data, 0 );
	GET_UINT32( W[1], data, 4 );
	GET_UINT32( W[2], data, 8 );
	GET_UINT32( W[3], data, 12 );
	GET_UINT32( W[4], data, 16 );
	GET_UINT32( W[5], data, 20 );
	GET_UINT32( W[6], data, 24 );
	GET_UINT32( W[7], data, 28 );
	GET_UINT32( W[8], data, 32 );
	GET_UINT32( W[9], data, 36 );
	GET_UINT32( W[10], data, 40 );
	GET_UINT32( W[11], data, 44 );
	GET_UINT32( W[12], data, 48 );
	GET_UINT32( W[13], data, 52 );
	GET_UINT32( W[14], data, 56 );
	GET_UINT32( W[15], data, 60 );

#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define R(t)                            			\
(                                     				\
	temp = W[(t - 3) & 0x0F] ^ W[(t - 8) & 0x0F] ^ 	\
	  W[(t - 14) & 0x0F] ^ W[ t     & 0x0F],     	\
	( W[t & 0x0F] = S(temp,1) )                 	\
)

#define P(a,b,c,d,e,x)                       		\
{                                     				\
	e += S(a,5) + F(b,c,d) + K + x; b = S(b,30);  	\
}

	A = ctx->state[0];
	B = ctx->state[1];
	C = ctx->state[2];
	D = ctx->state[3];
	E = ctx->state[4];

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

	P( A, B, C, D, E, W[0] );
	P( E, A, B, C, D, W[1] );
	P( D, E, A, B, C, W[2] );
	P( C, D, E, A, B, W[3] );
	P( B, C, D, E, A, W[4] );
	P( A, B, C, D, E, W[5] );
	P( E, A, B, C, D, W[6] );
	P( D, E, A, B, C, W[7] );
	P( C, D, E, A, B, W[8] );
	P( B, C, D, E, A, W[9] );
	P( A, B, C, D, E, W[10] );
	P( E, A, B, C, D, W[11] );
	P( D, E, A, B, C, W[12] );
	P( C, D, E, A, B, W[13] );
	P( B, C, D, E, A, W[14] );
	P( A, B, C, D, E, W[15] );
	P( E, A, B, C, D, R(16) );
	P( D, E, A, B, C, R(17) );
	P( C, D, E, A, B, R(18) );
	P( B, C, D, E, A, R(19) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1

	P( A, B, C, D, E, R(20) );
	P( E, A, B, C, D, R(21) );
	P( D, E, A, B, C, R(22) );
	P( C, D, E, A, B, R(23) );
	P( B, C, D, E, A, R(24) );
	P( A, B, C, D, E, R(25) );
	P( E, A, B, C, D, R(26) );
	P( D, E, A, B, C, R(27) );
	P( C, D, E, A, B, R(28) );
	P( B, C, D, E, A, R(29) );
	P( A, B, C, D, E, R(30) );
	P( E, A, B, C, D, R(31) );
	P( D, E, A, B, C, R(32) );
	P( C, D, E, A, B, R(33) );
	P( B, C, D, E, A, R(34) );
	P( A, B, C, D, E, R(35) );
	P( E, A, B, C, D, R(36) );
	P( D, E, A, B, C, R(37) );
	P( C, D, E, A, B, R(38) );
	P( B, C, D, E, A, R(39) );

#undef K
#undef F

#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

	P( A, B, C, D, E, R(40) );
	P( E, A, B, C, D, R(41) );
	P( D, E, A, B, C, R(42) );
	P( C, D, E, A, B, R(43) );
	P( B, C, D, E, A, R(44) );
	P( A, B, C, D, E, R(45) );
	P( E, A, B, C, D, R(46) );
	P( D, E, A, B, C, R(47) );
	P( C, D, E, A, B, R(48) );
	P( B, C, D, E, A, R(49) );
	P( A, B, C, D, E, R(50) );
	P( E, A, B, C, D, R(51) );
	P( D, E, A, B, C, R(52) );
	P( C, D, E, A, B, R(53) );
	P( B, C, D, E, A, R(54) );
	P( A, B, C, D, E, R(55) );
	P( E, A, B, C, D, R(56) );
	P( D, E, A, B, C, R(57) );
	P( C, D, E, A, B, R(58) );
	P( B, C, D, E, A, R(59) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6

	P( A, B, C, D, E, R(60) );
	P( E, A, B, C, D, R(61) );
	P( D, E, A, B, C, R(62) );
	P( C, D, E, A, B, R(63) );
	P( B, C, D, E, A, R(64) );
	P( A, B, C, D, E, R(65) );
	P( E, A, B, C, D, R(66) );
	P( D, E, A, B, C, R(67) );
	P( C, D, E, A, B, R(68) );
	P( B, C, D, E, A, R(69) );
	P( A, B, C, D, E, R(70) );
	P( E, A, B, C, D, R(71) );
	P( D, E, A, B, C, R(72) );
	P( C, D, E, A, B, R(73) );
	P( B, C, D, E, A, R(74) );
	P( A, B, C, D, E, R(75) );
	P( E, A, B, C, D, R(76) );
	P( D, E, A, B, C, R(77) );
	P( C, D, E, A, B, R(78) );
	P( B, C, D, E, A, R(79) );

#undef K
#undef F

	ctx->state[0] += A;
	ctx->state[1] += B;
	ctx->state[2] += C;
	ctx->state[3] += D;
	ctx->state[4] += E;
}

void sha1_update(sha1_context *ctx, uint8 *input, uint32 length)
{
	uint32 left, fill;

	if (!length) return;

	left = ctx->total[0] & 0x3F;
	fill = 64 - left;

	ctx->total[0] += length;
	ctx->total[0] &= 0xFFFFFFFF;

	if (ctx->total[0] < length)
		ctx->total[1]++;

	if (left && length >= fill)
	{
		memcpy((void *) (ctx->buffer + left), (void *) input, fill);
		sha1_process( ctx, ctx->buffer );
		length -= fill;
		input += fill;
		left = 0;
	}

	while (length >= 64)
	{
		sha1_process( ctx, input );
		length -= 64;
		input += 64;
	}

	if (length)
	{
		memcpy((void *) (ctx->buffer + left), (void *) input, length);
	}
}

static uint8 sha1_padding[64] =
{
 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

void sha1_finish(sha1_context *ctx, uint8 digest[20])
{
	uint32 last, padn;
	uint32 high, low;
	uint8 msglen[8];

	high = ( ctx->total[0] >> 29 ) | ( ctx->total[1] << 3 );
	low = ( ctx->total[0] << 3 );

	PUT_UINT32( high, msglen, 0 );
	PUT_UINT32( low, msglen, 4 );

	last = ctx->total[0] & 0x3F;
	padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );

	sha1_update( ctx, sha1_padding, padn );
	sha1_update( ctx, msglen, 8 );

	PUT_UINT32( ctx->state[0], digest, 0 );
	PUT_UINT32( ctx->state[1], digest, 4 );
	PUT_UINT32( ctx->state[2], digest, 8 );
	PUT_UINT32( ctx->state[3], digest, 12 );
	PUT_UINT32( ctx->state[4], digest, 16 );
}


 

